This invention relates to a method for treating "light posters" or paper sheets bearing printed picture images for illuminated display.
In the production of the so-called "light poster" which has a sign or a picture image printed on one side thereof for illuminated display on a light box, it is the usual practice to coat a solution of polyvinyl chloride on the back side of the printed paper sheet to increase its light transmittivity or to provide the poster in the form of a laminate with outer layers of polyester films. However, such existing light posters are still inferior in light transmittivity and incapable of showing the signs or picture images with satisfactory sharpness. In addition, the laminated films tend to soften and peel off during use over a long period of time.